Sorry, climate change deniers, but the global warming 'pause' still never happened

[Image credit: Shutterstock / Barnaby Chambers]

Another day, another series of ridiculous and incorrect claims about global warming getting far more air than they deserve.

The latest comes from none other than David Rose, a man who has serially misunderstood climate change so consistently that if he told me the sun would rise tomorrow, I'd be more inclined to believe the Earth had stopped rotating. He writes articles for the Daily Mail —it would be an insult to the fish to wrap them in this tabloid — and he uses a lot of typical techniques wielded by deniers, including cherry picking and misdirection. While he doesn't always deny global warming is happening, he does think it's not as bad as scientists say. I'll also note he has claimed the world is cooling, too, despite all the evidence (and I do mean all of it).

But if you deny what the overwhelming majority of climate scientists are telling you, then in my opinion that makes you a denier.

So what's new? Rose and some other climate change deniers claim that global temperatures have flattened out in the past 20 years or so. This is called a "pause" or hiatus in warming. However, last year, scientists from the National Oceanic and Atmospheric Administration (NOAA) came out with a paper showing that global warming has not slowed at all, and the pause wasn't real. But Rose claims to have a whistleblower from the NOAA who says that scientists improperly managed and misused the temperature data measuring global warming. If the data are wrong, the deniers reason, then the pause must be real.

The problem? This is all nonsense. The data are fine, the pause never happened, temperatures are still rising apace, and Rose gets it all wrong.

First, the "pause" is a claim that global warming has stopped since 1998 or so. This claim was never really true. 1998 was an unusually warm year, so if you start your measurements there it doesn't look like temperatures have risen much. But if you go back farther in time, the upward trend is very obvious. You have to look at the trend, and not short-term fluctuations!

Trend and variation

Still, scientists like to review the data they use to make sure they're accurate. Rose's article deals with a specific set of measurements of ocean water temperatures (I'll describe this briefly here, but for details please read an earlier article I wrote). Historically, this has been done using ships. This is problematic for various reasons; different ships use different methods, and worse, some scoop up water via intake pipes and pump it to the engine room, where the temperature of the water is measured. But this tends to warm the water up, leading to inaccurate measurements.

In more recent times buoys and floats have been used to do this, and they are far more accurate. In a paper published last year, scientists showed this and applied carefully calibrated corrections to the data. When they did, they showed pretty clearly that the global warming "pause" never really happened.

In his article, Rose calls these data into question. He makes a lot of claims in that article, but these claims are sweepingly wrong. If you want details, I urge you to read these articles by climate scientists outlining (and detailing) just where Rose is off the mark:

- In The Guardian, John Abraham points out that Rose's whistleblower never worked on the data.

- Zeke Hausfather, with Berkeley Earth, wrote a scathing rebuttal to Rose's claims at Carbon Brief — seriously, read this article if no other. Not so incidentally, he was also the lead researcher on a paper that independently verified the results of the original ocean temperature study.

- Another scientist, Victor Venema, ably disposes of Rose's claims at his blog Variable Variability.

- Climatologist Peter Thorne just simply destroys Rose's claims point by point at ICARUS.

Together these show that Rose is, as usual, grossly exaggerating the death of global warming.

The reason I'm writing my own post is that I predicted something like this. As I read Rose's article, one part made me chuckle ruefully. As I said above, in the (accurate and well-done) research paper that started all this, the scientists show the buoy measurements are better than ships because the water measured on ships was first pumped into the ships' engine rooms, warming it. The whole point of the paper was to correct for that artificial warming.

There are two ways to do this. One is to correct the ship measurements down, since the water was warmed up. Another way is to recalibrate the buoy temperatures up, to match the ship measurements. Now pay attention here: If you were looking at absolute temperatures — graphing the actual water temperatures, like, "the water from this part of the ocean at this time was at this temperature"— then you'd probably prefer to calibrate the ship temperatures down. That makes them more accurate.

However, climate scientists don't usually look at absolute temperatures -- they look at relative ones, what they call temperature anomalies. In other words, they use some baseline (say, temperatures from 1951 – 1980), take the average and measure everything relative to that. So if that average is, say, 10°C over that three decade range, and you measure the water temperature in 2005 as 11.8°C, you'd say the temperature anomaly in 2005 is +1.8°. Scientists typically do this to make it easier to see changes in the temperature, which is, after all, what global warming is.

Here's the fun part. Ships have been measuring water temperatures for a long time and are generally used as standards. So the scientists decided to recalibrate the buoy data up to match them. Remember, if you're measuring absolute temperatures then that gives you the wrong numbers, but not if you're measuring relative changes. If you add to the cooler temperatures or subtract from the warmer ones you get the same relative change. So it doesn't matter which way you do it.

Rose, however, quotes his whistleblower as saying, "They had good data from buoys. And they threw it out and 'corrected' it by using the bad data from ships. You never change good data to agree with bad, but that's what they did – so as to make it look as if the sea was warmer."

As I show, this is wrong. Since they weren't interested in absolute temperatures it didn't matter which way they recalibrated. Also, they didn’t "throw out" any data. They simply adjusted it.

The reason I found this grimly amusing is that a month ago I was looking into this very thing! I read the research paper and was momentarily a bit confused as to why they recalibrated the way they did. In an email exchange with a climate scientist I pointed out that this could get confusing to the public. It's obvious to a scientist that it doesn't matter since temperatures graphed are relative, but I feared that it could be misinterpreted. And that's exactly what Rose (and his whistleblower) did.

As I wrote to the scientist,

Most people don't have the experience with graphs that scientists do, so anything but absolute measures can be difficult to explain. Anomalies aren't too bad, but then try to explain why a good measurement (buoys) is adjusted to match the bad ones (ships)! Arg! I know it makes no difference to a scientist (and would be useful if ship measurements are considered the standard, even if off a bit), but to a layperson they'd question your sanity for doing that.

And here we are. I hate being right sometimes.

This shows that there can sometimes be a disconnect between the honest research of scientists and the way the public perceives that research. It's not anyone's fault really; the scientists are using the best methods and practices they have to understand reality, but the public gets and processes their information differently (not in a worse way, just different). It reminds me of the trouble we get using the word "theory"; to a scientist it means an extremely well-tested and reliable idea, but to the public it means more like a "guess." Same word, different uses, and it can give someone the wrong idea when used in the wrong context.

So why is all this important? Because publishing untrue claims like Rose's gives fodder to politicians who deny the reality of climate change. One of the most infamous is Rep. Lamar Smith (R-Texas), who is also the chair of the House Committee on Science, Space, and Technology. Funded by fossil fuel interests, he has long cranked the engine of denial, and in fact the Committee issued a press release based on Rose's whistleblower! They've been tweeting other hugely misleading statements about climate change recently as well.

And this is from the House Science Committee. They'd feel right at home in George Orwell's 1984.

And mind you, all this is happening in an environment where the President of the United States feels free to lie outrageously about science, including global warming. His cabinet picks are all climate change deniers to one degree or another, and science agencies are under attack. This is a positive feedback mechanism, where deniers like Rose will be emboldened to make more ridiculous claims, which in turn will be used to fuel the politicians' denial.

Is there hope? Yes. I'm heartened greatly by the public outcry defending science. This is making a difference; many Senators are stating that their phone lines are swamped with public complaints about President Trump's nominees and policies, and many have changed their stance. We have to keep this pressure up. Science is based on facts — real facts, not "alternative" facts — and reality will continue doing what it does whether politicians believe in it or not.